Building a pickguard from thin acrylic plastic seems a wee bit daft.
It is a bit daft, but not unique to the CS signature. All Ric pickguards except for the 4002 are made of acrylic sheet.
The first 4000 Series guards were back-painted clear acrylic, as were the RCA 4004s and the 75th Anniversary guards. Pre-'75 TRC's were also back-painted Plexiglas. Even some of the white Plexi guards are back-painted - when the white acrylic is slightly transparent.
I also don't like that the white guards don't age when the white binding and inlays are already ambered. Back-painted white guards (and TRC's) at least age nicely.